3 research outputs found
Tuning linkage isomerism and magnetic properties of bi- and tri-metallic cage silsesquioxanes by cation and solvent effects
No full textInternational audienc
Unusual Tri‑, Hexa‑, and Nonanuclear Cu(II) Cage Methylsilsesquioxanes: Synthesis, Structures, and Catalytic Activity in Oxidations with Peroxides
No full textThree
types of unusual cagelike copperÂ(II) methylsilsesquioxanes, namely,
nona- [(MeSiO<sub>1.5</sub>)<sub>18</sub>(CuO)<sub>9</sub>] <b>1</b>, hexa- [(MeSiO<sub>1.5</sub>)<sub>10</sub>(HO<sub>0.5</sub>)<sub>2</sub>(CuO)<sub>6</sub>Â​(C<sub>12</sub>H<sub>8</sub>N<sub>2</sub>)<sub>2</sub>Â(MeSiO<sub>1.5</sub>)<sub>10</sub>(HO<sub>0.5</sub>)<sub>1.33</sub>Â​(CH<sub>3</sub>COO<sub>0.5</sub>)<sub>0.67</sub>(CuO)<sub>6</sub>Â(C<sub>12</sub>H<sub>8</sub>N<sub>2</sub>)<sub>2</sub>] <b>2</b>, [(MeSiO<sub>1.5</sub>)<sub>10</sub>(CuO)<sub>6</sub>Â​(MeO<sub>0.5</sub>)<sub>2</sub>Â(C<sub>10</sub>H<sub>8</sub>N<sub>2</sub>)<sub>2</sub>] <b>3</b>, and trinuclear [(MeSiO<sub>1.5</sub>)<sub>8</sub>Â​(CuO)<sub>3</sub>(C<sub>10</sub>H<sub>8</sub>N<sub>2</sub>)<sub>2</sub>] <b>4</b>, were obtained in 44%,
27%, 20%, and 16% yields, respectively. Nuclearity and structural
fashion of products was controlled by the choice of solvent system
and ligand, specifically assisting the assembling of cage. Structures
of <b>1</b>–<b>4</b> were determined by single-crystal
X-ray diffraction analysis. Compounds <b>1</b> and <b>4</b> are the first cage metallasilsesquioxanes, containing nine and three
Cu ions, respectively. Product <b>1</b> is the first observation
of nonanuclear metallasilsesquioxane ever. Unique architecture of <b>4</b> represents early unknown type of molecular geometry, based
on two condensed pentamembered siloxane cycles. Topological analysis
of metal clusters in products <b>1</b>–<b>4</b> is provided. Complex <b>1</b> efficiently catalyzes oxidation
of alcohols with <i>tert</i>-butylhydroperoxide TBHP to
ketones or alkanes with H<sub>2</sub>O<sub>2</sub> to alkyl hydroperoxides
in acetonitrile
